Chair chassis

ABSTRACT

A chair chassis, comprising a chassis pedestal, a left and a right connecting rod for back, a seat supporting frame, an adjusting handle, the adjusting handle comprises an adjusting screw rod. On the adjusting screw rod exists a locating block for mounting handle and, the first pulling line and the second pulling line are wrapped around it, the two pulling lines are respectively used to lock or unlock the tilting angle of the back and to lock or unlock the position of the supporting frame; the adjusting handle also comprises a block for the pulling line, which is connected with the third pulling line, and the block for the pulling line is connected with the adjusting screw rod and, can relative slide on it. The invention is multi-functioned with the action of only one adjusting handle, and the structure of the invention is compact, and it is convenient to operate.

FIELD OF THE INVENTION

Embodiments of the present invention relate to a kind of the chairaccessories, and more specifically to a simple-structured, easy-operatedand ergonomic chair chassis.

BACKGROUND OF THE INVENTION

The current chair chassis only can achieve the basic function ofadjusting the height of chair to be adapted to the users, and when it isrelated to the condition that the back needs to be tilted or the seatneeds to be moved forward and backward, the controlling handle needs tobe applied, for instance, when a handle is used to adjust the tiltingangle of the seat, another handle is also needed to lock or unlock thetilting angle of the back; when we need to adjust the position of theseat, a handle will be needed, and there is also another handle for thelifting of the seat, so the number of the handles is quite a few, andthis will have art influence on the aesthetic of the whole chair.

When the height of chair is adjusted, the current chair is generallyadjusted by the handle, while it can't achieve the goal by rotating in360°.

SUMMARY OF THE INVENTION

In order to overcome the disadvantages of the prior art, the presentinvention provides a multi-function chair chassis, which is mounted byan adjusting handle, and it can provide the users comfortablecircumstance.

A chair chassis, comprising a chassis pedestal, on which exist a leftconnecting rod and a right connecting rod that are tiltable andconnected with the back; a supporting frame that can move forward andbackward, used to support the seat; an adjusting handle, which is fixedaxially on the chassis pedestal, wherein the adjusting handle comprisesan adjusting screw rod, and on one end of the adjusting screw rod existsspiral teeth, which can adjust the angle of the back by rotating.

A locating block for mounting handle is set on the adjusting screw rod,the first pulling line is wrapped around the locating block, and it canlock or unlock the right or the left tilting angle of the connectingrods.

A chair chassis according to embodiments of the present inventionincludes the second pulling line, which can lock and unlock the tiltingangle of the left and the right connecting rods for back, is wrappedaround the block for mounting handle, and the wrapping direction of thesecond pulling line is opposite to the wrapping direction of the firstpulling line.

The adjusting handle comprises a block for pulling line, the block isfixed with the third pulling line and, the block can relative slidealong the adjusting screw rod.

When the adjusting screw rod of the adjusting handle is turned around,the spiral teeth of the adjusting screw rod will adjust the tiltingelasticity of the left and the right connecting rods on the chassis, butthis is just the adjustment of the back's elasticity, and the tilting ofthe back will be further adjusted by the force of the users or otherforce; the locating block for mounting handle of the adjusting handlecan be adjusted in different directions, we can pull the first pullingline to lock or unlock the tilting angle of the connecting rods forback, we can also pull the second pulling line to lock or unlock thelocation of the supporting frame for seat; when we pull the block forpulling line along the direction of the adjusting handle, the thirdpulling line will be pulled to adjust the seat height of chair.

The invention have several advantages, such as, we can separatelycontrol the different parts of the adjusting handle, in order to controlthe tilting and the locking of the back, the locking of the seat and thelifting of chair, thereby providing a compact and easy-operatedstructure.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of the whole structure in accordance withthe present invention;

FIG. 2 is a schematic diagram of the FIG. 1 without the part of therubberizing shell;

FIG. 3 is a structural diagram of the handle of FIG. 1 in accordancewith the present invention;

FIG. 4 is a contrast structural diagram of the adjusting of the back'stilting in accordance with the present invention;

FIG. 5 is a contrast structural diagram of the tilting condition of theback in accordance with the present invention;

FIG. 6 is a contrast structural diagram of the back and forth moving ofthe seat in accordance with the present invention;

FIG. 7 is a structural diagram of the locking device of the back andforth moving of FIG. 6 in accordance with the present invention;

FIG. 8 is a schematic diagram of the locating and connecting of theadjusting handle and the elasticity-adjusting screw rod in accordancewith the present invention;

FIG. 9 is a structural diagram of the connecting of the rotating basefor torsion spring of FIG. 5 in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The following illustrations are further explanations of the invention,with the instructions of the concrete embodiment and figures.

Referring to FIGS. 1-9, the chair chassis comprises a chassis pedestal1; a left connecting rod 2 and a right connecting rod 2, which areconnected with the back and are tiltable and, they are set on thechassis pedestal 1; a supporting frame 4 for seat, used to support theforward and backward moving of the seat, an adjusting handle 3, settedalso on the chassis pedestal 1. The adjusting handle 3 comprises anadjusting screw 374, one end of the adjusting screw 374 exist the spiralteeth 373, which can be turned around to adjust the elasticity of theback.

The locating block for mounting handle 38 is set on the adjusting screwrod 374, and the first pulling line 902 is wrapped around the locatingblock 38 for mounting handle, the first pulling line can lock or unlockthe tilting angle of the back.

The second pulling line 900 is also wrapped around the locating block 38for mounting handle, which can lock or unlock the position of thesupporting frame 4; the winding direction of the second pulling line 900is opposite to the winding direction of the first pulling line 902.

The adjusting handle 3 comprises a block 36 for the pulling line, whichis connected with the third pulling line 901, and the block 36 for thepulling line is connected with the adjusting screw rod 374 and, canrelative slide on it.

The main protection parts of the invention: the adjusting handle 3 ofthe chassis pedestal 1 can achieve the tilting and the locking of theback, or/and the locking of the back's forward and backward moving,or/and the lifting control of the seat, that is, we can respectivelycontrol the spiral teeth 373 of the adjusting handle 3, the firstpulling line 902, the second pulling line 900 and the third pulling line901 to achieve the various control of the chassis.

Specifically, referring to FIG. 1, the chair chassis comprises thechassis pedestal 1, rubberizing shell 8, the left and the rightconnecting rods 2 for back, the supporting frame 4 for seat, theadjusting handle 3, the seat base 5, the position-control device 6 andthe supporting frame 7 for chassis. The connecting rods 2 are set on thetwo sides of the chassis pedestal 1 in the way of pivot joining, and theconnecting rods are connected with the back. The seat base 5 is axiallyset on the chassis pedestal 1, one end of the seat base 5 is fixed onthe chassis pedestal 1 with the action of the supporting frame 7 forchassis, the other end is fixed on the seat-supporting locating hole 21.The supporting frame 4 for seat is set on the supporting frame 7 forchassis and, can relative slide on it, more specifically is that,setting locating screw 51 for the supporting frame 4 on the chassissupporting frame 7, and setting a sliding-groove 41 for the supportingframe on the supporting frame 4 for seat, so that the locating screw 51for the supporting frame 4 can relative slide along the sliding-groove41, that is, the support frame 4 can move forward and backward on thechair chassis, and finally, the seat is fixed by the seat, locatingholes 42 on the supporting frame 4. The rubberizing shell 8 coordinateswith the chassis pedestal 1 to protect the inside mechanical structuresof the chassis, or to make it have a better outer frame. The adjustinghandle 3 is set on the chassis pedestal 1 with the action of block 39for the screw-rod sleeve. The position-control device 6 is used tocontrol the locking of unlocking of the forward and backward moving ofseat supporting frame 4.

Referring to FIG. 2, FIG. 4 and FIG. 5, the left and the rightconnecting rods 2 are connected with the chassis pedestal 1 with theaction of chassis shaft 15 in the way of pivot joining, the chassisshaft 15 is in the shape of six-angle bar and, passes across the chassispedestal 1, the two ends of the chassis shaft 15 are respectively fixedto the left and the right connecting rods 2. In the internal of thechassis pedestal 1 exists a torsion spring 101 and, the torsion spring101 is inside of the rotating base 16 for torsion spring, the torsionspring 101 is inside of the rotating base 16, the chassis shaft 15 isacross the rotating base 16 and the torsion spring 101 and, is fixed onthe rotating base 16, namely, on the two sides of the rotating base 16exist six-angle holes, the chassis shaft 15 passes through the six-angleholes of the rotating base 16 and is fixed with it. Between the chassisshaft 15 and the torsion spring 101 exists a plastic sleeve with theshape of six-angle bar, which is used to prevent the torsion spring 101from slipping, the rotating base 16 can rotate together with the chassisshaft 15.

There are two-torsion springs 101 that are both inside of the rotatingbase 16, and symmetric ring-sleeve is on the chassis shaft 15, both ofthe one end of the torsion spring 101 are respectively on the two endsof the cavity wall 160 of the rotating base 16 and, both of the otherend of the torsion spring 101 are on the sliding block 109 that is fixedat the bottom of the elasticity-adjusting screw rod 111, the center ofthe sliding block 109 is connected with the elasticity-adjusting screwrod 111 in the way of threaded connection, on the two sides of thesliding block 109 exist positioning stairs, the ends of the two torsionsprings 101 are just on the positioning stairs, on the top of theelasticity-adjusting screw rod 111 exists a turntable 108, when it turnsaround, the sliding block 109 can go up and down, and both of the otherend of the torsion spring 101 are respectively on the two ends of thecavity wall 160 of the rotating base 16, the torsion springs 101 arecompressed or loosed, thus, the adjusting the tilt of the connectingrods 2 is also the adjusting of the rotating base 16, so the forces aredifferent according to the elasticity of the torsion springs 101, whentorsion springs 101 are loosed, the rotating base 16 can easily rotateand, the connecting rods 2 can also be easily tilted; when torsionsprings 101 is compressed, the circumstance is absolutely contrary, inthis way, it can temporarily lock the tilting angle of the connectingrods 2, in order to lock the meshing of the first gear rack 103 and thesecond gear rack 104.

In the internal of the chassis pedestal 1 exists the first gear rack 103and second gear rack 104, which can mesh with each other, at the bottomof the rotating base 16 for torsion spring exists a sliding-groove, oneend of the first gear rack 103 is just fixed in the sliding-groove witha long-legged screw or a pin, shown as FIG. 9, the other end is insideof the chassis pedestal 1 and is movable. The second gear rack 104 ismeshed with the first gear rack 103 in the axial direction, in theinternal of the chassis pedestal 1 exists a sliding-groove 105 that isperpendicular to the first gear rack 103, the second gear rack 104 isinside of the sliding-groove 105 and, it can slide in the sliding-groove105, in order to mesh or separate with the first gear rack 103, in theback of the second gear rack 104 exists a strengthen spring 112 that isused to strengthen the meshing of the first gear rack 103 and the secondgear rack 104. When the second gear rack 104 is meshed with the firstgear rack 103, the limitation function of the second gear rack 104 canmake the first gear rack 103 be located, so that the rotating base 16for torsion spring is fixed and, the chassis shaft 15 is also fixed,finally, the left and the right connecting rods 2 are also fixed and,the tilting position of the back is fixed. When the tilting position ofthe back needs to be unlocked, we only need to loose the first gear rack103 and the second gear rack 104.

Referring to FIG. 7, the position-control device 6 that is at the bottomor on the side surface of the base 5 can be used to control the locatingof the forward and backward moving of the seat supporting frame 4, thestructure of the position-control device 6 is that, the position-controldevice 6 comprises a pedestal 61, a controlling block 63 for thepedestal, the controlling block 63 is set inside of the pedestal 61 withthe pedestal shall 66 in the way of pivot joining, the pedestal 61 isfixed by two screws 68 for the pedestal on the seat base 5, thesupporting frame 4 has tooth profiles, and on the controlling block 63for the pedestal also have controlling teeth 64, the controlling teeth64 can be meshed with the tooth profiles of the supporting frame 4,between the controlling block 63 and the pedestal 61 exists a spring 65for the supporting frame, which is used to strengthen the mesh of thecontrolling teeth 64 and the supporting frame 4. When the controllingteeth 64 is meshed with the supporting frame 4, the seat supportingframe 4 is located on the seat base 5, the seat is located on chairchassis, when the seat needs to be moved forward and backward, we justneed separate the controlling teeth 64 from the tooth profiles of thesupporting frame 4, and then the supporting frame 4 can move forward andbackward on the seat base 5.

Referring to FIG. 2, on the chassis pedestal 1 exists a mounting hole100 for pneumatic rod that is connected with the pneumatic rod, which isused in the process of the whole chair's lifting, the lever 14 forpneumatic rod, is used to adjust the lifting of the pneumatic rod, thelever 14 for pneumatic rod is connected with the chassis pedestal in theway of pivot joining, when the lever 14 for pneumatic rod is pulled, itcan control the lifting of the pneumatic rod, which is also the liftingof the chair chassis, when the lever 14 for pneumatic rod is loosed, thechair chassis is stopped from lifting.

The main protection parts of the invention are shown as FIG. 3, anadjusting handle 3 comprises an adjusting screw rod 374, a locatingblock 38 for handle, a screw rod sleeve 37, a block 36 for pulling line,an adjusting arm 35 and a knob 31, one end of the screw rod 374 existsthe screw teeth 373, the screw teeth 373 are meshed with the turntable108 to adjust the tilting angle of the connecting rods 2; the adjustingscrew rod 374 is inside of the screw rod 37, and the locating- block 38for handle is set on the screw rod sleeve 37 and, is fixed by a locatingpin. The locating block 38 is wrapped with the first pulling line 902and the second pulling line 900, in detail, on the locating block 38 forhandle exists two wire-grooves 384 and 383, on which are respectivelywrapped with the first pulling line 902 and the second pulling line 900and, the wrapping directions of the first pulling line 902 and thesecond pulling line 900 are contrary, separately, the first pulling line902 is connected with the second gear rack 104, used to adjust thelocking and unlocking of the tilting position of the back; while thesecond pulling line 900 is connected with the controlling block 63 forthe pedestal on the position-control device 6, used to adjust themeshing and separating of the controlling teeth 64 on the controllingblock 63 for the pedestal and the tooth profiles of the supporting frame4, so that, the locking or unlocking of the seat's forward and backwardmoving is controlled.

The end surface of the non-spiral teeth 373 of the adjusting screw rod374 is connected with the controlling block base 34, and the screw rodsleeve 374 is connected with the adjusting handle 35, which can moveaxially along the sleeve, that is, the adjusting handle 35 can moveaxially on the adjusting screw rod 374, but can't rotate, morespecifically is that, setting a platform on the adjusting screw rod 374that is matched with the adjusting handle 35 and, the holes on theadjusting handle 35 are matched with the platform, in other words, wecan make the shape of the end surface between the adjusting handle 35and the adjusting screw rod 374 be around, so that when we rotate theadjusting handle 35, the adjusting screw rod 374 will rotates togetherwith it.

The block 36 for pulling line is set on the adjusting handle 35 and canrelative rotate, in this invention, the relative rotation is that, theblock 36 for pulling line is mounted on the adjusting handle 35 and, canslide on it, and on the end surface of the adjusting handle 35 exists ablocking sheet 351 that can limit the axially moving of the block 36 forpulling line; the block 36 is fixed with the third pulling line 901 and,the third pulling line 901 is connected with the lever 14 for pneumaticrod, used to control the lifting of the whole chassis. In the rotationprocess of the adjusting handle 35, the adjusting screw rod 374 willrotate together, and in order to the prevent the third pulling line 901from being winded on the adjusting screw rod 374, caused by the frictionrotation between the block 36 and the adjusting handle 35, and, theinfluence on the third pulling line 901, it is necessary to limit therotation of the block 36, therefore, we can set the block 36 of theadjusting handle 35 inside of the screw rod sleeve 37 and, make theblock 36 be movable, namely, we can set two grooves in the screw rodsleeve 37 along the axial direction and, set two groove-blocks on theblock 36, which are matched with the grooves, so the groove-blocks cancoordinate with the grooves, and finally, we can set a groove 375 forthe pulling line on the screw rod sleeve 37, which is used to let thethird pulling line 901 pass through, so the third pulling line 901passed through the groove 375 with the action of the block 36 and, atlast, the third pulling line 901 is connected with the lever 14 forpneumatic rod. When the adjusting handle 35 is pulled, as the limitationof groove-block on the block 36, the block 36 is static, while theinside adjusting screw rod 374 will rotate; when the screw rod sleeve 37rotates alone, the adjusting screw rod 374 is static, the block 36 forthe pulling line and the screw rod sleeve 37 rotate together, thus, thethird pulling line 901 in the groove 375 will not be wrapped on theadjusting screw rod 374.

The controlling-block base 34 is inside of the adjusting handle 35, theadjusting handle 35 is fixed on the fixed block 32 that is face-to-facewith the controlling block base 34, the fixed block 32 is connected withthe internal thread of the adjusting handle 35, between the controllingblock base 34 and the fixed block 32 exists a controlling block 33, thecontrolling block 33 has an handle and, the handle is extended to theoutside of the hole of the fixed block 32 and it can swing in the holeof the fixed block 32 in any direction, when the handle-swings, as thecontrolling block 33 is set between the controlling block 34 and thefixed block 32, if the controlling block 33 is pulled, one end of itwill be located on the controlling block 34, the other end of it will betilted because of the lever principle and be fixed on the fixed block32, the controlling block base 34 and the adjusting screw rod 374 areaxially located on the chassis pedestal 1, thus, the controlling blockbase 34 is static and, the controlling block 33 will pry the fixed block32 and the adjusting handle 35 in the direction that is far away fromthe chassis pedestal 1, and the block 36 for pulling line on theadjusting handle 35 will move along the groove in the screw rod sleeve37 in the direction that is far away from the chassis pedestal 1, thus,the pulling line 901 will pull the lever 14, fixed with the end of thepulling line 901 and, achieve the goal that the whole chassis can be upand down.

The adjusting screw rod 374 is axially fixed on the chassis pedestal 1,shown as FIG. 8, the screw rod sleeve 37 is set on the chassis pedestal1 with the action of the block 39 for screw rod sleeve, morespecifically, on one end of the elasticity-adjusting screw rod 111exists a fixed iron-sheet 102 and, the iron-sheet 102 is above theturntable 108, we can make the top of the elasticity-adjusting screw rod111 be prism-shaped and, set diamond-shaped holes that can becoordinated with it, so that we can achieve the goal of fixing by makingthe diamond-shaped holes on the iron-sheet 102 be matched with theprism-shaped rod of the elasticity-adjusting screw rod 111, definitely,we can also achieve the goal of fixing by the above way, which makes thenon-circular shaft and the non-circular holes coordinate with the other.On one end of the iron-sheet 102 exists a vertical-plate and, on thevertical-plate exists a hole that the dimension of it is matched withthe dimension of the adjusting screw rod 374, the adjusting screw rod374 passes through the hole, and the hole will not restrict the rotationof the adjusting screw rod 374. The limiting sheet 107 is set on theiron-sheet 102 and, it is bent and is with the “7” shape, one side ofthe limiting sheet 107 is fixed on the iron-sheet 102 by screws, theother side is parallel to the vertical-plate, on the vertical edge ofthe limiting sheet 107 exists a hole, the dimension of which is matchedwith the dimension of the adjusting screw rod 374, the adjusting screwrod 374 passes through the hole, but the hole will not restrict therotation of the adjusting screw rod 37, and finally, we set a limitingpin between the vertical-plate and the vertical edge of the limitingsheet 107, the limiting pin can't pass through the vertical-plate andthe hole on the vertical edge of the limiting sheet 107, meanwhile, theiron-sheet 102, the vertical-plate, the limiting pin and the limitingsheet 107 also have the function of the locating of theelasticity-adjusting screw rod 111.

The screw rod sleeve 37 is connected with the adjusting handle 35 withthe action of the knob 31, on the outer surfaces of the screw rod sleeve37 and the adjusting handle 35 exist concave teeth 371 and 352, whichare set face-to-face and, can coordinate respectively with the convexteeth 311 on the inner surface of the knob 31, and also, the handle ofthe controlling block 33 is extended to the outside of the knob 31.Thus, when the knob 31 coordinates with the concave teeth 371 of thescrew rod sleeve 37, if the knob 31 is pulled, the screw rod sleeve 37will also rotate and, the locating block 38 for mounting handle alsorotates in different directions, so the one of the first pulling line902 and the second pulling line 900 of the locating block 38 for handlewill act, so the controlling teeth 64 will be meshed with or beseparated from the tooth profiles of the first gear rack 103 or thesupporting frame 4 to achieve the locking or the unlocking.

On the contrary, when the knob 31 coordinates with the concave teeth 352of the adjusting handle 35, if the knob 31 is pulled, the screw rodsleeve 37 is static, while the adjusting screw rod 374 that is connectedwith the screw rod sleeve 37 will rotate, so that the spiral s teeth 373are meshed with the turntable 108 and, the tilting angle of the back isadjusted.

Definitely, when the adjusting back is tilt, the first gear rack 103 ofthe chassis pedestal 1, and the second gear rack 104 should be firstlyseparated from the other, therefore, on the chassis pedestal 1 alsoexists a locating block 17 for the pulling line, which coordinates withthe locating block 38 for mounting handle, and the locating block 17 isfixed by a screw on the chassis pedestal 1, on the locating block 17 forthe pulling line exist the locating holes 173 for the first pulling line902, the locating hole 171 for the second pulling line 900, which arerespectively coordinated with the first pulling line 902 and the secondpulling line 900. The gear coordination is achieved by several geargrooves 172 that are set on the locating block 17 for the pulling line,and on the locating block 38 for mounting handle exist two gear blocks381 that are matched with the gear groove 172, the gear block 381 islocated in the gear groove 172, and the gear block 381 can move back andforth in the gear groove 172 by rotating the locating block 38 formounting handle. The ends of the first pulling line 902 and the secondpulling line 900 are located on the locating hole 382 for pulling lineof the gear block 381.

On the first pulling line 902, the second pulling line 900 and the thirdpulling line 901 respectively exist the locating block 106 for the firstpulling line, the locating block 67 for the second pulling line and thelocating block 114 for the third pulling line, which are corresponded tothe second gear rack 104, the controlling teeth 64 and the terminal oflever 14 for pneumatic rod. In order to prevent the oblique force of thefirst pulling line 902, the second pulling line 900 and the thirdpulling line 901, when the second gear rack 104, the controlling teeth64 and the lever 14 of pneumatic rod are respectively pulled, we shouldpull the line in the right direction to have the pulling line a longerlife and, to pull the line with the least force.

Detailed Operation of the Invention

1. Make the knob 31 be in coordination with the concave teeth 371 of thescrew rod sleeve 37, namely, the knob 31 slide towards the screw rodsleeve 37, and the knob 31 is turned to make the screw rod sleeve 37rotate, so that the locating block 38 for mounting handle also rotateswith it, then the first pulling line 902 separates from the second gearrack 104 and, mesh with the first gear rack 103, also, the gear block381 on the locating block for mounting handle 38 is located on the geargroove 172 of the block 17 for the pulling line.

Make the knob 31 be in coordination with the adjusting handle 35,namely, let the knob 31 return back, and turn around the knob 31, tomake the adjusting screw rod 374 that is in connection with theadjusting handle 35 rotates, and the spiral teeth 373 of the adjustingscrew rod 374 will mesh with the other and rotate together, then thesliding block 109 is lifted and, the elasticity of the torsion spring101 decreases, at this time, if the user compresses the back, thechassis shaft 15 will be pushed to rotate and, make the rotating base 16for torsion spring also rotate, then the knob 31 will be turned aroundin the opposite direction, then the elasticity of the torsion spring 101increases.

Finally, the knob 31 is coordinated with the concave teeth 371 of thescrew rod sleeve 37 and is turned around to make the second gear rack104 mesh with the first gear rack 103, so that the back is adjusted andlocked.

2. Make the knob 31 be in coordination with the concave teeth 371 of thescrew rod sleeve 37, namely, the knob 31 slides towards the screw rodsleeve 37 and, is turned around to make the screw rod sleeve 37 alsorotate, so that the block 38 for mounting handle will rotate with it,the second pulling line 900 makes the controlling teeth 64 separate fromthe support frame 4, and this adjusts the seat to the appropriateposition, then the knob 31 is turned around in the opposite direction tomake the controlling teeth 64 return to the original position. Thus, theabove operation completes the adjustment of the seat and the lockingfunction.

3. Swing the handle of the controlling block 33 in any direction, tomake the fixed block 32 and the adjusting handle 35 be axially locatedon the chassis pedestal 1 with the action of the adjusting screw rod 374and the controlling block base 34, so the fixed block 32 and theadjusting handle 35 will be far away from the spiral teeth 373, and thenthis makes the block 36 pull the third pulling line 901, and finally,the lever 14 for pneumatic rod is pulled to adjust the lift of the wholechair, when the handle of the controlling block 33 returns back, thelever 14 will also return back to stop the lifting.

While, the present invention has been illustrated by the abovedescription of the preferred embodiments and figures thereof, while thepreferred embodiments have been described in considerable detail, it isnot intended to restrict or in any way limit the scope of the appendedclaims to such details, other advantages and modification skilled in theart. Therefore, the present invention is not limited to the specificdetails and the illustrative examples shown and described.

1. A chair chassis, comprising a chassis pedestal, on which exist a leftconnecting rod and a right connecting rod that are tiltable andconnected with the back; a supporting frame that can move forward andbackward, used to support the seat; an adjusting handle, which is fixedaxially on the chassis pedestal, wherein the adjusting handle comprisesan adjusting screw rod, and on one end of the adjusting screw rod existsspiral teeth, which can adjust the angle of the back by rotating. Alocating block for mounting handle is set on the adjusting screw rod,the first pull line is wrapped around the locating block, and the firstpulling line can lock or unlock the right or the left tilting angle ofthe connecting rods.
 2. The chair chassis of claim 1, wherein the secondpulling line, which can lock and unlock the tilting angle of the leftand the right connecting rods for back, is wrapped around the block formounting handle.
 3. The chair chassis of claim 1, wherein the adjustinghandle comprises a block for pulling line, and the block is fixed withthe third pulling line and, the block can relative slide along theadjusting screw rod.
 4. The chair chassis of claim 1, wherein theadjusting handle comprises a screw-rod sleeve and, the adjusting screwrod is inside of it, the locating block for mounting handle is fixed onthe screw rod sleeve; On the chassis pedestal also exists a locatingblock for pulling line that coordinates with the block for mountinghandle, and on the block exists the first pulling line, the locatinghole of the first pulling line for the second pulling line, the locatinghole of the second pulling line.
 5. The chair chassis of claim 3,wherein the end surface of the non-spiral teeth is connected with acontrolling block base, and on the adjusting screw rod sleeve exists anadjusting handle that can slide axially along it, the controlling blockbase is in the internal of the adjusting handle, the block for pullingline is on the adjusting handle and can relatively rotate with it and,inside of the adjusting handle exists a fixed block with holes that isface-to-face with the controlling block base; between the controllingblock base and the fixed block exists a controlling block, and thehandle of the controlling block is extended to outer of the holes of thefixed block, the handle of the controlling block can swing freely in anydirection in the hole of the fixed block.
 6. The chair chassis of claim5, wherein the screw rod sleeve is connected with the adjusting handlewith the action of the knob, which is outside of the sliding sleeve, andthe knob coordinates with the screw rod sleeve, the surface of theadjusting handle by the meshing of the concave and convex teeth, thehandle of the controlling block is extended to the outer of the knob. 7.The chair chassis of claim 5, wherein the left and right connecting rodsfor back are connected with the chassis pedestal by the chassis shaft inthe way of pivot joining, in the chassis pedestal exists torsionsprings, torsion spring rotating base, the torsion spring is inside ofthe torsion spring rotating base, the chassis shaft passes through thetorsion spring rotating base and the torsion spring and, is fixed on thetorsion spring rotating base, the two ends of the chassis shaft arerespectively connected to the left and the right connecting rods forback. One end of the torsion spring is on the cavity wall of therotating base and, the other end is on the sliding block that is fixedat the bottom of the elasticity-adjusting screw rod, on the top of theelasticity-adjustment screw rod exists a turntable that is meshed withthe spiral teeth; In the internal of the chassis pedestal exists thefirst gear rack and the second gear rack, which can mesh with the other,one end of the first gear rack is fixed in the sliding groove that is onthe torsion spring rotating base, the other side is freely set; thesecond gear rack can slide inside the chassis pedestal, so that it canmesh with or separate from the first gear rack, the second gear rack isconnected to the first pulling line.
 8. The chair chassis of claim 2,wherein the supporting frame for seat is set on the seat bracket that ison the two sides of the chassis pedestal, and it can relative slide onthe seat bracket, at the bottom or the side surface of the supportingframe for seat exists a position-control device, the device comprises abase and, the controlling teeth that are connected with the base in theway of pivot joining, the controlling teeth are meshed with the teeth ofthe supporting frame for seat, the controlling teeth are connected withthe second pulling line.
 9. The chair chassis of claim 3, wherein on thechassis pedestal exists a mounting-hole for pneumatic rod that isconnected with the pneumatic rod, the lever for pneumatic rod is on themounting-hole of pneumatic rod and is connected with the chassispedestal in the way of pivot joining, and the lever for pneumatic rod isconnected with the third pulling line.
 10. The chair chassis of any aclaim of claims 4, wherein on the first pulling line, the second pullingline and the third pulling line respectively exist the locating blockfor the first pulling line, the locating block for the second pullingline and the locating block for the third pulling line, which arecorresponded to the second gear rack, the controlling teeth and theterminal of lever for pneumatic rod.